On 05/26/2010 11:31 AM, Alexander Graf wrote:>> On 26.05.2010, at 19:10, Orion Poplawski wrote:>>> On 05/25/2010 12:21 AM, Gleb Natapov wrote:>>> Adding kvm to CC.>>>>>> On Mon, May 24, 2010 at 04:06:32PM +0000, Orion Poplawski wrote:>>>> I have a KVM virtual machine running 2.6.33.4-95.fc13.x86_64 on a CentOS 5.5>>>> host whose clock jumps about 8-12 hours a couple times a day. I have no idea>>>> what is causing it. Fedora 12 and Centos 5.5 KVM machines run fine on the same>>>> host. Is there any debugging I can enable to see what is jumping the clock?>>>>>>>> kvm-clock: cpu 0, msr 0:1ba4741, boot clock>>>> kvm-clock: cpu 0, msr 0:1e15741, primary cpu clock>>>> Switching to clocksource kvm-clock>>>> rtc_cmos 00:01: setting system clock to 2010-05-20 16:59:48 UTC (1274374788)>>>>>> Thanks, though I don't think it made it there. I'm also not sure it's completely limited to KVM, though that is the only running system I am currently seeing the problem on. I also see clock jumps during anaconda installs on physical hardware and apparently they have been present since at least F11. Might be unrelated though.>>>> I'm really at a loss of how to debug this though.>> Do you have ntpd running inside the guest? I have a bug report lying around about 2.6.33 with kvm-clock jumping in time when ntpd is used: https://bugzilla.novell.com/show_bug.cgi?id=582260>> Alex>

That bug looks just like what I'm seeing. I even see the soft lockup messages sometimes as well. May actually be seeing it with a Fedora 12 guest as well - but it results in a hard hang.